CAT 291-6526 Drive Adapter Needle Bearing

CAT 291-6526 is a Caterpillar original equipment manufacturer (OEM) needle roller bearing with inner ring (with cage and seal). It is compatible with the planetary gears of the Cat 320D/323D excavator slewing gearbox and the second-shaft gear of the 242D/252D skid steer loader transmission. Its core design is for bearing heavy radial loads in compact spaces, suitable for low-speed, high-torque conditions, ensuring efficient operation of transmission components. The following is complete professional information:

Core Technical Parameters (Professional Version)

Item Details
Basic Attributes
Model: 291-6526, Type: Inner ring needle roller bearing (with inner ring/outer ring/needle roller/stamped cage/double-sided seal), Compatible with the planetary gears of the Cat 320D/323D excavator slewing gearbox and the second-shaft gear of the 242D/252D skid steer loader transmission, Material: High carbon chromium bearing steel (GCr15, integrally hardened), Inner diameter: φ60 mm, Outer diameter: φ85 mm, Width: 25 mm mm, single weight approximately 0.62 kg, rated radial load 95 kN, operating temperature -40℃ to +120℃, suitable shaft speed ≤3500 rpm, suitable journal tolerance f7, bearing housing bore tolerance H7, radial clearance C2 grade (small clearance, suitable for precision transmission)

Key Dimensions: Inner diameter tolerance 0/-0.015 mm, outer diameter tolerance +0.020/-0.010 mm, width tolerance ±0.12 mm, needle roller diameter φ3 mm, number of needle rollers 45, needle roller length 22 mm, cage made of stamped steel plate, end seals made of nitrile rubber (NBR), axial clearance 0.020-0.030 mm, suitable journal diameter φ60 mm (tolerance f7), bearing housing bore inner diameter ≥85 mm, depth ≥25 mm

Material and Manufacturing Process: Inner ring/outer ring material GCr15 (hardness after quenching) HRC 60-64), raceway surface hardened layer depth 1.8-2.2 mm, core hardness HRC 30-35, needle roller material GCr15 (hardness HRC 62-66), cage made of ST12 low carbon steel stamping, surface galvanized for corrosion protection, needle roller surface roughness Ra≤0.2 μm, end chamfer 1.5×45°, coaxiality ≤0.03 mm, needle roller and cage pocket clearance 0.15-0.20 mm. Compatible with Cat 320D/323D excavators (serial number JBT1000-UP) rotary gearbox planetary gear bearings and 242D/252D skid steer loaders (serial number JCB1000-UP) gearbox second shaft gear bearings. Used for radial support of planetary gears and second shaft gears, suitable for low speed (≤1200 rpm) and high torque (≤500 rpm). Under operating conditions of N·m, ensure smooth transmission of the drive system and avoid premature wear caused by gear uneven loading.

Assembly Fit: Outer ring with bearing housing bore interference fit (interference 0.010-0.015 mm), inner ring with shaft interference fit (interference 0.012-0.018 mm), rear end face runout ≤0.04 mm, radial runout ≤0.08 mm, uniform raceway contact marks, no local contact stress concentration.

Installation and Maintenance Points: Before installation, clean the bearing housing bore and journal, check for rust/needle roller jamming/seal damage, and press the bearing in smoothly using a special press-fit tool. Do not strike the inner/outer ring end faces to prevent needle roller bending or cage deformation.

After installation, add Cat-specific extreme pressure grease (NLGI grade 2), replenishing every 800 hours to ensure sufficient lubrication of the needle rollers and raceways, and that the seals are intact to prevent dust/moisture ingress.

Maintenance recommendations: Stop the machine immediately for inspection if the bearing operating temperature is >90℃ or abnormal noise occurs. Replace the bearing if the needle roller wear is >0.15 mm or if surface peeling occurs. Regularly check the bearing housing seal to prevent grease leakage, which can lead to increased dry friction and wear.